The Chemistry of Powder and Explosives - Sciencemadness Dot Org

TRINITROBENZENE 135
powder, 250 liters of 95 per cent alcohol, and 25 liters of water,
refluxed together for 2 hours and filtered hot; the TNB crystallizes
out m good yield when the liquid is cooled
The nitration of m-dmitrobenzene is too expensive of acid and
of heat for practical application, and the yields are poor Toluene
and chlorobenzene are nitrated more easily and more economically,
and their tnnitro compounds are feasible materials for the
preparation of TNB Oxidation with nitrosulfunc acid has obvious
disadvantages. The quickest, most convenient, and cheapest
method is probably that in which TNT is oxidized by means of
chromic acid in sulfunc acid solution
Preparation of Tnnitrobenzene A mixture of 30 grams of punned
TNT and 300 cc of concentrated sulfunc icid is introduced into a tall
beaker, which stands m an empty agateware basin, and the mixture is
stirred actrvely by means of an electnc stirrer while powdered sodium
dichromate (Na2Cr2Oi2H.O) is added m small portions at a time, care
being taken that no lumps are formed and that none floats on the surface
of the liquid The temperature of the liquid rises When it has
reached 40°, cold water is poured into the basin and the addition of
dichromate is continued, with stirring, until 45 grams has been added,
the temperature being kept alwajs between 40° and 50° The mixture
is stirred for 2 hours longer at the same temperature, and is then allowed
to cool and to stand over night, m order that the tnmtrobenzoic
acid may absume a coarser crystalline form and may be filtered off more
readily The strongly acid liquid is filtered through an asbestos filter;
the solid material is rinsed with cold water and transferred to a beaker
in wliich it is treated with warm water at 50° sufficient to dissolve all
«oluble matenal The w arm solution is filtered, and boiled until no more
tnmtrobenzene precipitates The crystals of TNB growing m the hot
aqueous liquid often attain a length of several millimeters When filtered
from the cooled liquid and rinsed with water, they are practically
l>ure, almobt colorless or greenish vellow leaflets, mp 121-122°.
Tiimtiobenzcne is only moderately soluble in hot alcohol, more
leadily in acetone, ether, and benzene Like other polymtro
aromatic compounds it forms colored molecular compounds with
many aromatic hydrocarbons and organic bases. 8 The compound
s Couipaie Hep]), Antt, 215, 356 (1882), Sudborough, J Chem Soc, 75,
588 (1889), 79, 522 (1901), 83, 1334 (1903), 89, 583 (1906); 97, 773
(1910), 99, 209 (1911), 109, 1339 (1916), Sachs and Steinert, Ber., 37,
1745 (1904), Xolting and Somnierhoff, ibid, 39, 76 (1906), Kremann, ibid,
39, 1022 (1906), Ciiiba, Gazz chim ital, 43, II, 91 (1913), Ciusa and